PHP extension development: How to define the input parameters and return value types of custom functions?

In PHP extension development, it is very important to define the input parameters and return value types of custom functions. Specific steps include: Define type qualifier: void no return value, use int as the basic type, etc., use arrayobject as the object type, any The type uses mixed. Define the input parameter type: use the zend_arg_info structure to specify the parameter name, type, and whether to pass by reference. Define the return value type: use zend_return_reference * pointer, specify the type and whether null is allowed. Register a custom function: use zend_register_functions and pass in parameter and return value type information.

PHP extension development: define custom function input parameters and return value types

In PHP extension development, define custom The parameter and return value types of a function are crucial to ensuring security and code stability. The following are the steps:

1. Define type qualifiers

PHP provides several type qualifiers for specifying parameter types and return values:

• void: For functions that do not return a value
• int, float, string, bool: used for basic data types
• array
• ##object: used for objects
• mixed: Used to accept any type of parameters

2. Define the input parameter type

The input parameter type can be used

zend_arg_info Structure definition:

zend_arg_info arg_info[] = {
  { .name = "argument_name", .type = type, .pass_by_reference = 0 },
  // ... 更多参数
  { .name = NULL, .type = 0 }
};

Among them:

• argument_name: parameter name
• type: type qualification Symbol
• pass_by_reference: Whether to pass parameters by reference (default is 0, pass by value)

3. Define the return value type

The return value type can use

zend_return_reference * Pointer definition:

zend_return_reference *return_reference;
if (return_value) {
  return_reference->type = type;
  return_reference->allow_null = 1;
}

Among them:

• type: type qualification Symbol
• allow_null: Whether to allow the return value to be null

4. Register the custom function

Finally, Use the

zend_register_functions function to register a custom function and pass in the specified parameter and return value type information:

zend_function_entry functions[] = {
  { "my_function_name", ZEND_FN(my_function_name), ZEND_FN(my_function_name), arg_info, return_reference },
  // ... 其他函数
};

zend_register_functions(functions, COUNT_OF(functions));

Practical case

Let’s write A custom function named

add() that accepts two integer parameters and returns an integer.

zend_arg_info arg_info[] = {
  { .name = "num1", .type = IS_LONG, .pass_by_reference = 0 },
  { .name = "num2", .type = IS_LONG, .pass_by_reference = 0 },
  { .name = NULL, .type = 0 }
};

zend_return_reference *return_reference;
return_reference->type = IS_LONG;
return_reference->allow_null = 0;

ZEND_FUNCTION(add) {
  long num1, num2;
  ZEND_PARSE_PARAMETERS_START(2, 2)
    Z_PARAM_LONG(num1)
    Z_PARAM_LONG(num2)
  ZEND_PARSE_PARAMETERS_END();

  RETURN_LONG(num1 + num2);
}

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